Implementação de modelos de microplanos para análise não-Linear de estruturas de concreto, uma abordagem orientada a objetos

• Ano de defesa: 2002
• Autor(a) principal: Patrick Perez Ramos Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Microplanos; Análise não-linear; Engenharia de estruturas
• Link de acesso: http://hdl.handle.net/1843/FACO-5JVLJR

This work presents the evaluation results of two microplane models (the Explicit Microplane Model and the Microplane model with Relaxed Kinematic Constraint) to nonlinear analysis of concrete structures by finite element method. The main elements of a nonlinear physical analysis are studied shortly. The limitations of orthotropic constitutive models with scalar damage are discussed and the microplane models are presented as an alternative approach. The evolution of these models is shortly shown. The formulation used to obtain the stress state and the stiffness degradation of a material point, based on the definition of a set of planes (microplanes) and on the validity of stress-strain laws to each microplane, is discussed. Using object oriented programming methodology, implementations details are presented. Numericalsimulations of axial compression, axial tension and shear tests show that the Explicit Microplane Model presents serious numerical instability problems and the Microplane Model with Relaxed Constraint is more stable to the same tests. Then, this model is used to simulates other tests in plain concrete structures, presenting good results for different stress states. Finally, the behavior of the Microplane Model with RelaxedKinematic Constraint, to simulate reinforced concrete structures, is investigated in a such way that considers the steel as a elastoplastic material and perfect bond between concrete and steel.